The TRILL protocol is a routing protocol based on link state calculation in a layer-2 (data link layer) network. A device that runs the TRILL protocol is called a RB. A network including RBs is called a TRILL campus.
To ensure access reliability of a customer edge (CE) device, the CE device generally accesses multiple edge RBs and then accesses a TRILL campus using the multiple edge RBs, which forms a multi-homing access situation. The multiple edge RBs are referred to as a multi-homing access group of the CE device below. There are two working manners of a multi-homing access group. One is an active/standby manner, and the other is an active/active manner.
In the active/standby manner, for a virtual local area network (VLAN) accessed by the multi-homing access group, only one edge RB in the multi-homing access group is allowed to send and receive a packet sent by a CE device in the VLAN to and from the TRILL campus, where the edge RB is referred to as an appointed forwarder (AF). The AF periodically broadcasts a TRILL Hello packet to other edge RBs in the multi-homing access group using an access link of the AF. When the access link of the AF is faulty, the AF cannot send the TRILL Hello packet using the access link. If one or more other edge RBs that is in the same multi-homing access group as the AF does not receive the TRILL Hello packet within predetermined time, for example, N (N is configurable and is three by default) TRILL Hello packet sending periods, the one or more other edge RBs determines that the access link of the AF is faulty, performs TRILL protocol processing, and resets a packet forwarding rule. In the active/active manner, the TRILL Hello packet is not sent among multiple edge RBs in a multi-homing access group. If a fault occurs in an access link of one edge RB, other edge RBs cannot learn the fault, and a CE device still sends data to the faulty edge RB.
In a process of implementing the present disclosure, the prior art has the following disadvantages.
In the active/standby manner, after a fault occurs in an edge RB in a multi-homing access group, other edge RBs can perceive the fault of the edge RB only after set time, and then formulate a new packet forwarding rule, resulting in a low network convergence speed. In the active/active manner, after a fault occurs in an edge RB in a multi-homing access group, because edge RBs do not send a TRILL Hello packet to each other over an access link for negotiation, other edge RBs cannot learn the fault of the edge RB, resulting in a packet loss and decreased network reliability.